Step forging presses utilizing a plurality of discrete die segments and utilizing a pressure means for forcing the die segments into an associated work blank to produce a formed part are known in the art. Such prior art pressure means includes an endless belt-like arrangement of a plurality of rollers which provides for applying pressure to the discrete die segments in a pressure zone as the work passes through the pressure zone.
U.S. Pat. No. 3,847,004 dated Nov. 12, 1974 in the name of August R. Bringewald and entitled Apparatus and Method for Applying Pressure and Die and Method for Forming a Part, and U.S. Pat. No. 4,608,848 dated Sept. 2, 1986 to Joseph J. Mele and entitled Part Forming Apparatus by Flow Forging, are examples of such prior art arrangements.
Also, U.S. Pat. No. 3,415,095 dated Dec. 10, 1968 to A. R. Bringewald and entitled Process and Apparatus for Producing Metal Plates With Integral Stiffeners, and U.S. Pat. No. 3,521,472 dated July 21, 1970 in the name of A. R. Bringewald and entitled Process and Apparatus for the Production of Parts From Ductile Metals With Integral Stiffeners on One or Both Sides, disclose the use of a pair of relatively large pressure rollers for forming a part from a ductile blank, but wherein unitary die structure is utilized rather than using discrete die segments of the first identified prior art patents.